A data lab buys as principal: one counterparty, one price, and the price is theirs. An intermediary acting for the seller runs the buyers for you. The difference shows up in two places, who sets the price and whether you can license again.
Buying as principal
The firm licenses your record itself and resells it to the labs under its own paper. It is quick and it is one conversation. The terms it publishes are often a perpetual exclusive licence, which means that record is sold once, at the smallest it will ever be, and never licensed again.
Acting for the seller
The intermediary writes a codename teaser, puts the asset in front of one buyer at a time with a twenty four hour clock, and brings back a real read. Your name reaches no buyer before a mutual NDA. The licence is non-exclusive unless a buyer pays for a defined period and you agree to it.
What to ask either one
Is the licence exclusive, and for how long. Who sets the price and against what. When the money is due, and whether any of it is owed if no buyer ever pays. What they do with the personal data in the record. Get the answers in writing before the long form.
What Artemis does
Acts for the seller. No fee, no commission, no retainer to you. Non-exclusive by default. Payment is a signing amount, a share of what the buyer pays, and a floor on a named date.